Forming apparatus and method for constructing concrete columns

ABSTRACT

The current invention discloses moisture resistant column forms constructed from corrugated plastic. The forms disclosed herein are lightweight and can be easily assembled at a construction site or remote location. The forms can be positioned over pre-placed sections of reinforcing bars, or sections of reinforcing bars can be placed into a form once it is in position. The forms disclosed in the current invention can be easily removed, but they do not attract insects and therefore do not have to be removed from columns after the concrete has dried. The forms disclosed herein have generally square perimeters when they are assembled and put in place, but after concrete is poured into the form, the side walls will undergo uniform deformation/displacement due to the hydrostatic pressure of the concrete and the resulting column will have a generally circular perimeter. A method of using the forms is also disclosed.

TECHNICAL FIELD

The invention relates to a form that allows piers or columns to be created from poured concrete, for use in building construction. In particular, this invention describes a lightweight and collapsible form for columns.

BACKGROUND OF THE INVENTION

Concrete columns are commonly used as upright supports for buildings and other structures. These concrete support structures exist in a wide variety of shapes. Typically, these concrete supports have circular, square or rectangular cross-sections and the size of the support varies depending upon the intended use.

The concrete foundation for a structure anchors the entire structure against settling, slippage and wind lift. It also distributes loads into the ground and protects posts or beams from direct contact with the earth. The foundation may consist of two parts, a footing that distributes the load underground and a pier that raises the bottom of a structure above grade. In some installations the pier performs both functions.

In the past, forms for these columns were made from steel or wood. Concrete is poured into these forms and allowed to harden. After hardening, the forms are removed from the concrete structure and can be used again. While steel and wood forms are adequate for construction of columns, the materials used to make these forms can be costly. Additionally, constructing column forms from steel or wood is a labor intensive process that requires some degree of skill.

Another type of form used for columns in the more recent past is elongated paper fiber tubes. The tubes are made by spirally winding several layers of strong fiber paper. The spirally wound paper is laminated along its seams with a special adhesive. Concrete is poured into the tube and allowed to harden so as to form a column. After hardening, the tube is generally stripped away from the concrete column and scrapped. An example of a paper fiber tube for use in constructing columns can be seen in U.S. Pat. No. 2,914,833.

When paper fiber tubes are left in place for an extended period, before concrete is poured into them, they can deteriorate. To overcome this problem, the tubes can be coated with a water resistant material such as wax.

Another problem associated with paper fiber tubes is that the tube can soak up some of the water from the wet concrete. When this occurs, the tube can be difficult to remove from the concrete, or the resulting column can be stained. A variety of methods are used to overcome this problem, including the use of plastic liners, coating the tube interiors with plastic, and providing tear strips to ease the removal of the tubes. U.S. Pat. Nos. 5,595,168, 4,957,270, and 6,467,749 are examples of some of these methods. Additionally, tubes constructed from composite materials have been used to overcome this problem. U.S. Pat. No. 6,295,782 is an example of such a tube.

To store the tubes, they are either stacked horizontally or vertically. This storage requires considerable floor space in storage facilities, and considerable cargo space when the tubes are transported to a construction site thereby resulting in significant costs and inconvenience. U.S. Pat. Nos. 5,328,142 and 5,376,316, both issued to Weekers describe lightweight tubes that address the storage space issue.

The tubes in the Weekers patents are made from thin walls of wound pater layers which permit the tubes to be collapsed and wound into a real to facilitate shipment and storage. While the tubes disclosed in the Weekers patents are easier to store, it can be difficult to get the tubes to stand upright, without additional support, when they are being used to form longer columns.

Thus there exists a need for a moisture resistant form for concrete columns that is easily stored and transported, and that can be used without any additional supports. Such forms that are light weight and do not require significant storage space would be an improvement over the prior art.

DISCLOSURE OF THE INVENTION

Disclosed herein is a form for concrete columns that overcomes the disadvantages of the prior art by providing a form which is prefabricate at a remote location and can be quickly installed on a construction site for considerably less cost than wood forms. The forms disclosed herein are resistant to moisture so it can be used in a greater variety of climates than cardboard forms.

The forms disclosed herein are constructed of light weight corrugated plastic. Corrugated plastic is well-known material having two parallel facing sheets and spaced, integral interconnecting ribs between the facing sheets. The plastic sheet material can be easily extruded from a variety of plastic resins such as polyethylene, polypropylene, and the like. This material is also referred to as fluted plastic. However, for the purpose of this invention any reference to corrugated plastic is a reference to a material comprising two parallel facing sheets of some plastic composite, having spaced, integral interconnecting ribs between them.

The forms disclosed herein have four side walls such that the shape of the form as seen from above would be square. The forms are generally constructed from a single piece of corrugated plastic. Folds or seams in the plastic define the corners of the form, and the free edges of the piece of plastic are secured to each other with an adhesive material such as construction glue or the like. The forms can be constructed in a variety of sizes and heights.

In their collapsed configuration the forms are easily stored and transported. At a construction site, the forms can be easily assembled. To assemble, the forms are unfolded and positioned in the location where a concrete column is to be constructed. If desired, sections of reinforcing bar can be placed in the forms to provide reinforcement for the concrete columns. Concrete is then poured into the top of the form, and the hydrostatic pressure of the concrete causes uniform displacement/deformation of the form side walls such that the resulting column is cylindrical.

Because they are constructed of corrugated plastic, the forms disclosed herein will not attract insects and can therefore be left on the cured columns. However, the forms need not be left on the columns and they can be easily removed by scoring the forms along the vertical length of the column and pealing the form away from the cured column.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features disclosed herein, which are believed to be novel, are set forth in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following descriptions, taken in conjunction with the accompanying drawings wherein:

FIG. 1 is an elevated perspective view showing a plurality of forms, according to the disclosure herein, stacked for storage or transportation.

FIG. 2 is an elevated perspective view of a preferred embodiment of a column form disclosed herein, with a plurality of reinforcing bars placed into the form.

FIG. 3 is a view showing the structure of the corrugated plastic walls of a preferred embodiment of a column form disclosed herein.

FIG. 4 is an elevated perspective view of concrete being poured into a preferred embodiment of a column form disclosed herein.

FIG. 5 is an elevated perspective view of a column form after concrete has been poured into the form, and the form walls have undergone deformation due to the hydrostatic pressure of the concrete.

BEST MODE OF CARRYING OUT THE INVENTION

Turning now to the drawings, the invention will be described in a preferred embodiment by reference to the numerals of the drawings wherein like numbers indicate like parts.

FIG. 1 shows a preferred embodiment of the pier/column form disclosed herein wherein several forms 10 are folded and stacked for storage or transportation to a construction site. As can be seen in FIG. 2 and FIG. 3, the forms disclosed herein are constructed from corrugated plastic and have four side walls that define an elongated form with an interior for the placement of concrete, and having a generally square cross sectional shape when viewed from above.

In at least one preferred embodiment, the form is constructed from a single piece of corrugated plastic that has a plurality of seams/folds, which define the corners of the form. The free edges of the sheet of corrugated plastic can be overlapped and connected with an adhesive such as construction glue of the like or other connection means can be used.

Referring again to FIG. 1, the forms 10 can be folded, along two of the seams 18 & 16 such that the form will lay flat. The embodiment depicted in FIG. 1 includes a plurality of dashed lines 21 evenly spaced along the form. The dashed lines 21 can be used as measuring guides, so that the form can be easily cut to a desired length. In at least one preferred embodiment, the dashed lines are spaced one foot apart.

Also shown on the embodiment of the form depicted in FIG. 1 are a plurality of flanges 19. The flanges 19 are formed from the same piece of corrugated plastic as the form 10, and they are created by cutting a small slot in the corrugated plastic along each of the corner seams. The flanges 19 are located at the bottom of the form and they are used for securing the form in a desired location on a construction site.

Referring to FIG. 2, there is shown a form 10 placed on a concrete pier block 30. The embodiment depicted four side walls 11-14, and seams in the piece of corrugated plastic define the corners of the form 15-18. The flanges 19 on the form are folded out from the form and they are laying flat on the pier block.

As can be seen in FIG. 2, each flange can include one or more holes so that the form can be secured in position using some type of stake or other anchoring device. The anchoring devices can be used when a form is placed directly on the substrate or when a form is placed on some type of prepared foundation such as a pier block. When used on a pier block, flanges can also be secured in position with a non-permanent adhesive or caulk if desired.

A plurality of reinforcing bars 31 can be seen inside the form depicted in FIG. 2. When reinforcing bars are desired in a column, the bars can be put in place and the form can be placed over the bars (as would be the case where the bars are secured to other sections of reinforcing bars that protrude up from a pier block or foundation footing) or the reinforcing bars can be lowered into a form that is already in its desired location.

FIG. 3 is a detailed view of one embodiment of corrugated plastic used for the forms disclosed herein. As can be seen in the figure, the integral interconnecting ribs in this embodiment extend at an angle from the two facing sheets of plastic material. However, other embodiments of the forms disclosed herein are made from corrugated plastic having integral interconnecting ribs that extend at other angles from the two facing sheets of plastic material. In at least one preferred embodiment, the interconnecting ribs extend at right angles from the two facing sheets of plastic material.

The corrugated plastic used to create the forms disclosed herein must be thick enough to resist tearing under the hydrostatic pressure of the concrete in the form. Thus the minimum thickness of the sidewalls will be based on the desired dimensions of the resulting columns. Preferred embodiments of the forms disclosed herein can be constructed from corrugated plastic having a thickness in the range of {fraction (3/16)} of an inch to 1 inch, and at least one preferred embodiment has a thickness of {fraction (9/16)} of an inch.

FIG. 4 depicts a load of concrete 40 being poured into the interior of a form, and FIG. 5 shows the displacement/deformation of the form side walls under the hydrostatic pressure of the concrete 40.

While the displacement/deformation of the side walls is generally uniform in nature along the length of the form, the lower sections of the column may not displace uniformly with the rest of the column This is especially true when the form is staked to a substrate, as opposed to being placed on some type of foundation or pier block. The resulting column will have a base that is non-uniform to the rest of the column, but there will be no loss of structural strength due to the non-uniform base.

To use the forms disclosed herein, a user selects forms of the desired size and cuts the forms to the desired length of the columns to be constructed. The forms are placed in the desired location (either on a pier block, base, foundation footing, or prepared substrate). If reinforcing bars are desired, they can be secured in position and the form lowered over them or they can be placed inside the form after it is placed in its desired location. If desired, the form can be secured in the desired location using stakes, caulk, or other means. Concrete is then poured into the forms and the form sidewalls undergo deformation/displacement due to the hydrostatic pressure of the concrete. After the concrete has been poured, the resultant generally cylindrical columns are allowed to cure.

The forms disclosed herein are constructed from corrugated plastic. They are lightweight, easily transported, easily stored, easily assembled, and easily used. They are less expensive than forms constructed from wood, and they are moisture resistant. Unlike forms constructed from cardboard, so they can be left in position for a long period of time before concrete is poured. While they are easily removed from the cured columns, the forms disclosed in the current invention do not attract insects, so there is no need to remove the forms from the finished columns.

The forms disclosed herein can positioned over pre-placed reinforcing bars or reinforcing bars can be placed into the form after it is in position.

While the embodiments of the forms described herein were described as being made from a single piece of corrugated plastic material, other preferred embodiments can be constructed from a plurality of pieces of plastic material that are connected to each other in a manner similar the free edges of the form made from a single piece of corrugated plastic.

Industrial Applicability

The invention has applicability in the field of construction using concrete. In particular the current invention describes forms for concrete columns/piers. The forms disclosed herein are constructed from corrugated plastic and they are lightweight, easily transported, easily stored, easily assembled, and easily used. They are less expensive than forms constructed from wood, and they are moisture resistant, unlike forms constructed from cardboard. Therefore, the forms disclosed herein are suitable for constructing structures having residential or commercial applications.

To use the current invention, a builder simply assembles the forms at the construction site by folding the one piece forms into the desired shape If reinforcing bars are desired the forms can be positioned over pre-placed reinforcing bars or reinforcing bars can be placed in the form after it is in position. The forms can be staked to the ground or otherwise secured in their desired location. Concrete is then poured into the forms and allowed to set. While the forms disclosed herein can be easily removed, they do not attract insects, so they do not have to be removed from the columns.

In compliance with the statute, the invention has been described in language more or less specific as to structural features. It is to be understood, however, that the invention is not limited to the specific features shown, since the means and construction shown comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims, appropriately interpreted in accordance with the doctrine of equivalents. 

1. A form for constructing a concrete column comprising: four substantially planar side walls made from corrugated plastic having spaced, integral interconnecting ribs between two facing sheets of plastic; each side wall having a long axis, a short axis, a first side, a second side, an interior surface an exterior surface, a top edge, and a bottom edge; and the first side of each side wall being immediately adjacent to the second side of another of the side walls such that a corner is formed at each side of the side walls, thereby defining a form interior for the placement of concrete and an exterior.
 2. The form of claim 1 further comprising means for securing the form in a desired location at a construction site.
 3. A form for constructing a concrete column comprising: four substantially planar side walls made from corrugated plastic having spaced, integral interconnecting ribs between two facing sheets of plastic; each side wall having a long axis, a short axis, a first side, a second side, an interior surface an exterior surface, a top edge, and a bottom edge; and the first side of each side wall being immediately adjacent to the second side of another of the side walls such that a corner is formed at each side of the side walls, thereby defining a form interior for the placement of concrete and an exterior.
 4. The form of claim 3 wherein the form comprises one piece of corrugated plastic having spaced, integral interconnecting ribs between two facing sheets of plastic; the piece of corrugated plastic having a long axis, a short axis, and two connecting edges; the piece of corrugated plastic further having three seams at right angles to the long axis whereby the seams define the four side walls of the form; and the connecting edges of the piece of corrugated plastic are connected to each other.
 5. The form of claim 4 wherein the edges of the piece of corrugated plastic are connected to each other by an adhesive substance.
 6. The form of claim 3 wherein the form comprises a plurality of pieces of corrugated plastic having spaced, integral interconnecting ribs between two facing sheets of plastic; each piece of corrugated plastic having a long axis, a short axis, a first edge and a second edge; and the first edge of each piece of corrugated plastic is connected to the second edge of another pieces of corrugated plastic.
 7. The form of claim 3 further comprising flanges located at the bottom edge of the side walls and the flanges are configured such that the form can be secured in a desired location.
 8. The form of claim 7 wherein the flanges are integral to the side walls and are defined by a seam running parallel to the long axis of the side walls along the bottom edge of the side walls.
 9. The form of claim 7 wherein the flanges are constructed from a separate piece of corrugated plastic than the side walls and the flanges are connected to the side walls along the bottom edge of the side walls.
 10. The form of claim 3 wherein the exterior of the form includes a plurality of dashed lines at a right angle to the long axis of the side walls and the dashed lines are evenly spaced along the long axis of the side walls to provide a measuring guide for cutting the form to a desired length.
 11. The form of claim 3 wherein the four side walls define a generally square perimeter when viewed from above and when concrete is poured into the form, the hydrostatic pressure exerted on the side walls by the concrete causes uniform displacement of the side walls such that the generally square perimeter assumes a generally circular shape, and the resulting column is generally cylindrical.
 12. The form of claim 3 further including means for securing the form in a desired location.
 13. A method for constructing a concrete column comprising the steps of: (a) selecting a location for constructing the column; (b) preparing the location for construction of the column; (c) selecting a form for construction of the column that comprises four substantially planar side walls made from corrugated plastic having spaced, integral interconnecting ribs between two facing sheets of plastic; each side wall having a long axis, a short axis, a first side, a second side, an interior surface an exterior surface, a top edge, and a bottom edge; the first side of each side wall being immediately adjacent to the second side of another of the side walls such that a corner is formed at each side of the side walls, thereby defining a form interior for the placement of concrete and an exterior; (d) positioning the form in the selected location; (e) pouring concrete into the form; and (f) allowing the concrete to harden.
 14. The method of claim 13 wherein the form that is positioned in the selected location further comprises means for securing the form in a selected location at a construction site.
 15. The method of claim 13 wherein the method has the additional step of securing the form in its selected location before the step of pouring concrete into the form.
 16. The method of claim 13 wherein the form is positioned over sections of reinforcing bar that are pre-placed at the desired location.
 17. The method of claim 13 wherein after the form is positioned in the desired location, sections of reinforcing bar are placed in the interior of the form before concrete is poured into the interior of the form.
 18. The method of claim 13 wherein the four side walls of the form that is positioned in the selected location define a generally square perimeter when viewed from above and when concrete is poured into the form, the hydrostatic pressure exerted on the side walls by the concrete causes uniform displacement of the side walls such that the generally square perimeter assumes a generally circular shape, and the resulting column is generally cylindrical. 